The PV system (Fig.1) which is the subject of this study is located in a site characterized by these coordinated geographical. This site has a Northern latitude equal to 22°, a longitude 6° and an altitude 1400m. PV generator of this system is a power of 750-Watts peak and it has a surface of 6 m2. It is directed towards the south is tilted towards north with an angle equal to 10°. This system east constitutes by the following elements:

1. A PV field, which is consisted of 16 sell panels, each module with a power of 45 Watts peak. The maximum tension is 40 V and its maximum current is 20 A.

2. A battery which consists of 12 lead accumulators of 2 V each one connected in series to ensure a nominal voltage of 24 V

3. An inverter for converts the tension continues with an alternating voltage

4. A regulator which makes it possible to manage the circulation of current between the battery and the load

The monitoring of a PV system consists in following its operation through the fine measurements taken using an automatic measurement chain. This

operation allows to control the operation of the system on the one hand and to detect the possible anomalies of the failures which can this present on the one hand and to detect the information on the reliability of the elements constitute the system and on its capacity to satisfy the load. Thus, thanks to the database which it provides, monitoring makes it possible to determine the performance of PV system considered, to evaluate the quality of its sizing and to optimize the various elements.